Vehicle Body Flow Suppression Device

1. A vehicle body drifting restraining device restraining a drifting of a vehicle body of a vehicle, the vehicle body drifting restraining device comprising: an activeness level determination unit determining an activeness level of a driver with respect to a movement of the vehicle in a longitudinal direction; and a vehicle body drifting restraining control permission/prohibition switch permitting or prohibiting a control restraining the drifting of the vehicle body, wherein the control restraining the drifting of the vehicle body is executed only when the activeness level determination unit determines that the activeness level is low, the control restraining the drifting of the vehicle body restrains the drifting of the vehicle body with respect to a lateral slope of a road surface, the control restraining the drifting of the vehicle body prevents the vehicle body from drifting towards a lower portion of a road surface, and the control restraining the drifting of the vehicle body is executed based on a steering torque of the vehicle running straight.

2. The vehicle body drifting restraining device according to claim 1 , further comprising: a longitudinal acceleration detection unit detecting an acceleration of the vehicle in a longitudinal direction, wherein the activeness level determination unit determines that the activeness level of the driver is low when the acceleration of the vehicle in the longitudinal direction, detected by the longitudinal acceleration detection unit, is less than a predetermined value.

3. The vehicle body drifting restraining device according to claim 1 , further comprising: an accelerator opening detection unit detecting an accelerator opening of the vehicle, wherein the activeness level determination unit determines that the activeness level of the driver is low when, either the accelerator opening detected by the accelerator opening detection unit is less than a predetermined value, or, a temporal change in the accelerator opening is less than a predetermined value.

4. The vehicle body drifting restraining device according to claim 1 , further comprising: a vehicle behavior determination unit determining a behavior of the vehicle; and a driver performance determination unit determining a driver performance of the vehicle, wherein whether or not the vehicle is running straight is determined based on a determination result of the vehicle behavior determination unit and the driver performance determination unit.

5. The vehicle drifting restraining device according to claim 1 , further comprising; a vehicle behavior determination unit determining a behavior of the vehicle, wherein the activeness level determination unit further determines the activeness level of a driver based on the determined behavior of the vehicle.

6. The vehicle drifting restraining device according to claim 5 , wherein when the determined behavior of the vehicle is a cruising motion, the activeness level of the driver is determined to be low.